Bad Astronomy

Vesta in breathtaking detail

NASA’s Dawn mission team just revealed the first full-frame image of the giant main-belt asteroid Vesta, and it’s really, really cool:

Yegads! [Click to asteroidenate.]

Vesta is about 500 km (300 miles) across, but is clearly non-spherical, so take that as an average. That’s roughly the size of Colorado! So it’s a big rock, and we’re now seeing it in exquisite detail. This image was taken on July 24, from a distance of about 5000 km (3000 miles).

Man, there’s nothing like being there.

There’s a lot to see. The surface of Vesta is varied, with craters of various sizes (as expected) and depths. I’m very curious to see that there are some darker spots (like in this image) that look like material dredged up from under the surface from impacts; we see this on the Moon and other bodies as well. Some preliminary mineralogical maps show varied distributions of minerals on the surface as well.

An animation of Vesta rotating has also been put together, and really shows how odd this little world is:

[Make sure to set the resolution to at least 720p!]

Look at how the surface changes: you can see smoother regions, cratered regions, places that are darker, some where it’s brighter. Clearly Vesta has been battered over time – the entire south pole region is an impact basin, and those parallel grooves are from waves of energy moving through the asteroid during the impact event – and hopefully its history will be unraveled when higher-resolution images come in.

In fact, the scientists at the press conference talked at length about how these first images have raised a lot of questions, and stressed several times how more images will reveal the answers. Dawn will orbit Vesta for a full (Earth) year, so we should get plenty of data that will keep folks busy for a long time.

… and it won’t end there. After Dawn leaves Vesta it’ll head over the Ceres, the largest of the main belt asteroids. I wonder what it’ll find there? But it’s too soon to worry about that! We have a whole new world to explore for now.

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Related posts:

- Dawn of a new Vesta
- Dawn approaches
- On approach to Vesta
- Hubble spins an asteroid